Temporary Desert Structures

In the desert, one desires shelter from too much sun, wind, and dust. Although simple mountaineering tents can be completely sealed against wind and dust, they have the disadvantage of lacking headroom for standing and being too small for comfortable group gatherings. In addition, structures that achieve these shelter goals must be transported and erected easily.

Among the variety of structures seen at Burning Man every year, from the simplicity of overhead tarps and slab-sided vinyl car garages to the opposite extreme of mobile-home style offices, Domes and Yurts provide adequate shelter, are strong enough to withstand the Black Rock Desert environment, and require only moderate effort for assembly and disassembly.

Dome kits and yurt kits can be either hand-made or purchased. See the links for more information.

Hammocks

We all look forward to a hanging around some good swingers right ?

Tensile Structures

http://www.freeformtents.com/gallery.html

Domes

Many desert campers construct temporary shelters using a dome for a support frame. The frame supports a cover that either is draped on top or is suspended beneath. Some shelters use two covers, one occupying each position. Most dome covers are made from tarps, canvas, or agricultural shade cloth, such as Aluminet. Used parachutes also are used, with mixed results.

The two major kinds of dome frames are mentioned below.

Geodesic Domes

The frame of a geodesic dome is constructed from straight members which are connected to each other at their ends.

The frame members can be made from various materials, the two most popular being zinc-plated steel tubing and PVC plastic pipe. Renewable natural materials, such as bamboo and wood, although seen, are used much less frequently. The dome-makers’ attraction to non-structural tubing, whose primary building purpose is electrical-cable protection or water conveyance, probably is explained by the material’s easy fabrication and straightforward joint connection, as well as its moderate cost. Ordinary structural building materials, such as wooden 2×4s, although less expensive, require more extensive joint-connection systems involving steel plates or brackets.

Geodesic Frame Summary

Note 1: Configuration not recommended Note 2: PVC frames cannot support hammocks

Geodesic Frame Materials

Steel dome frames usually are constructed from thin-wall conduit a.k.a. EMT (electrical metal/mechanical tubing). These silver tubes usually are seen on the walls of buildings protecting surface-routed electrical cables from physical damage. EMT is fairly strong in lengths up to about five feet, depending on tubing diameter.

Most metal-frame domes are constructed from ³/₄-inch EMT. The largest domes use 1-inch EMT. EMT sizes are “nominal”, or true in name only, since the actual tubing diameters are greater. The actual diameter of “³/₄-inch” EMT is almost ¹⁵/₁₆ inch; the actual diameter of “1-inch” EMT is a little over 1-¹/₈ inches.

EMT conduit weighs about half a pound per linear foot, but because EMT cannot be used in full, uncut lengths, domes made with it either are small or must use more members. So for a given dome size, there is little weight advantage to using EMT. EMT is thinner than most other alternatives, however.

EMT dome frames are strong enough to support hammocks.

More information on EMT dome frames can be found at Tara Landry’s Desert Domes site.

PVC dome frames usually are constructed from white PVC irrigation pipe, in 10-foot lengths, with a wall thickness known in the building trade as “schedule 40”. Most times these pipes are connected at joints using loops of rope through holes drilled in the pipe ends, making a “Van Brink/Lerner” dome. Major advantages of rope-jointed PVC dome frames are their quick disassembly time and their relative low weight for a given dome size.

Most PVC-pipe dome frames are constructed from 2-inch PVC pipe. However, the variety of different PVC pipe diameters makes it possible to choose two or three different sizes of PVC pipe, allowing nesting during transport. When one uses this approach, one must be sure to use the thickest pipes for the upper horizontal members which must resist bending from the force of the wind.

As with EMT, PVC pipe sizes also are nominal. The actual diameter of “2-inch” PVC pipe is 2-³/₈ inches.

2-inch PVC pipe weighs about ²/₃ pound per linear foot.

PVC dome frames are not strong enough to support hammocks.

How does PVC hold up over the years? Does it become brittle?

Yes. PVC is a vinyl. They all tend to get hard and brittle over time, especially when exposed to UV (sunlight). The gray stuff that is sold as electrical conduit lasts longer when exposed to the sun, but is very hard to find in lengths over 10’.

More information on PVC dome frames can be found at Steve Lerner’s Web Site.

Bamboo dome frames are constructed in the same configuration as PVC dome frames, above. (More to come)

Wooden dome frames usually are found in the construction of dome homes but rarely are found in temporary structures. A notable exception is the 60-foot wooden-2×4 dome that was below the Man at Burning Man 2004. Another exception is Kerry’s 26-foot wooden-2×4 dome. The advantage of using an ordinary construction material is its strength and its low cost. Wooden frames can have much larger triangles than EMT conduit frames, for a given dome size, and so less material is needed for the frame, and doorways can be larger without removing frame members. The disadvantage of using wood is its weight and the extra expense required for metal joint-connection plates. Simple wooden dome frames can be connected easily using inexpensive Starplates. Larger domes require custom plates.

Wooden dome frames are strong enough to support hammocks, but the base plates of the smallest wooden frames must be anchored to the ground to prevent distortion from the lateral forces that hammocks apply.

Geodesic Dome Sizes

The size of a geodesic dome depends on the length of its frame members and on the frame’s frequency. Images of different dome frequencies can be found by going to this page and mousing over the labels 1V, 2V, …, 6V. Domes tend to be constructed in sizes that use readily available building materials without waste. The common sizes are mentioned below.

A dome’s frame is described by the diameter of the hemisphere that just fits around it. It is as if each of the frame’s joints is affixed to the inside of a ball, with straight members connecting adjacent joints.

The joints at the base of a dome form a circle. For 2V domes the dome diameter and the base diameter are the same. The height of a 2V dome is half of the dome diameter. For 1V and 3V domes, which are not perfect hemispheres, the base diameter is smaller than the dome diameter. The height of an odd-V dome can be either greater than or less than half of its diameter, depending on how it is made.

Lower-frequency dome frames are the most popular. Domes for individual camps tend to use 1V, 2V, or 3V frames. Domes with frequencies beyond 3V usually take large teams of people a long time to assemble.

1V Frame

1V dome frames have the longest members, and so they must be constructed from materials that can resist bending, such as 2-inch diameter PVC pipe or bamboo, or wooden 2×4s. One advantage of 1V domes is that all of the members of the frame have the same length, and so usually 1V domes use building materials uncut (PVC pipe in 10-foot lengths and wooden 2×4s in 8-foot lengths).

A 1V dome that is constructed from 10-foot PVC pipe members has a base diameter of 17 feet. Constructed from 8-foot wooden 2×4s, a 1V dome has a base diameter of 14 feet. In both cases, the members form triangular doorways that are large enough to pass through without stooping. 1V domes have 25 members, all the same length.

From Justin on the AEZ list: Last year, we had a wooden 1V geodesic, which is easy to put together using starplates. http://www.strombergschickens.com/

You simply buy 2×4’s the length you need, drill a single hole through the ends (we did this off playa) then bolt the whole shebang together. It took us about 2 hours to put up the frame, and we did it for the first time on the playa. The covering took a bit longer, as we hadn’t had a chance to try it all out before the burn (came in from abroad) but plan to do that this year properly. We used blue tarps which I’d like to replace with something better but canvas seems too expensive and I haven’t come up with anything else. Might try and stitch Velcro onto the tarps this year and staple the other Velcro side to the wood, see if that makes it a bit easer to put together and stop the walls flapping so much.

Jay’s photos of his starplate dome with Aluminet and tarp combination cover: http://www.flickr.com/photos/86101508@N00/ …my brother and I decided to use the starplate design along with an Aluminet cover for the sides and a more opaque, reflective fabric for the top surface. We sewed a skirt for the dome which we were able to slip on over the structure as we constructed it. Both fabrics were somewhat stretchy which made the process easier.

In the past we’ve made domes using a similar design but using 10’ PVC pipes held together using ropes and covered with a tarp. This design was relatively unsuccessful, we were forced to constantly make adjustments, preventing it from breaking apart and flying into our neighbors camp. Although the wood frame in the starplate design is heavier than PVC, it is a very simple and robust approach..

2V Frame

2V dome frames have a greater number of members, compared to a 1V frame with the same base diameter, but the members are shorter. Usually 2V domes are constructed from ³/₄-inch steel EMT conduit. Since metal conduit cannot resist bending sufficiently to be used in uncut 10-foot lengths, usually it is cut in half, making the members about 5 feet long. Not all members of a 2V dome have the same length: 35 of the members are longer than the remaining 30. If the long members of a dome frame have a length of 5 feet, the short members have a length of 4 feet-5 inches. Such a dome has a base diameter of 16 feet and a doorway height of 4 feet.

A 2V dome can be constructed from wooden 2×4s, with member lengths of 8 feet, and 7 feet-1 inch, as described under Wooden Dome Frames above. Such a dome has a base diameter of 26 feet, a ceiling height of 13 feet, and a doorway that is large enough to pass through without stooping.

3V Frame

3V dome frames can be used for larger EMT domes or when more ceiling height is wanted. Constructed from EMT tubing, a 3V dome frame can have a base diameter of 24 feet. The height of a 3V dome depends on whether it includes a short wall at the base. Including the base wall increases the ceiling height. Such a 3V dome is called “⁵/₈” and, in the case of a 24-foot dome, the ceiling height is 15 feet. This dome has 165 members. Omitting the wall creates a “³/₈” dome and results in a ceiling height of 9 feet. Such a dome has 120 members.

Non-geodesic Domes

PVC dome frames (bent pipe) also use white PVC irrigation pipe, but the pipes are much thinner and bend over the top of the frame.

Jolly Roger has created instructions for the style of dome used in the Mayor’s camp (the Baseball, the Beehive, the Easter Egg, the Frog, etc). In 2006, Katherine the Great created the Teddy Bear and the Unicorn Palace based on Roger’s design

How to build the PVC skeleton: PVCdome3.gif and pvcdome3.pdf (includes shopping list and helpful diagrams). Following these instructions, the dome is about 10 feet in diameter with 6-foot headroom inside (when using the optional center rib in the diagram). The design allows flexibility. Pull the perimeter rope tighter to make an 8-foot diameter dome with 8-foot headroom. Release the perimeter rope to make a 12 to 14-foot diameter dome with about 5-foot headroom.

Tip: use the longer kind of end-to-end slip-on PVC coupling, because otherwise your poles might come apart too easily.

“But what will I use to cover the dome?” Knitted fabrics work well, and the best way to get a ‘pattern’ is to set the dome up and pin all your fabric pieces in place over the dome.

Yurts and Yurt-like Structures

http://www.rdrop.com/~glacier/yurtPages/yurtGallery.html

http://www.bendersbjurts.com/

Cover Materials

From David on the AEZ list: …we have had great luck with spandex, that stretchy material. It stretches great, and made great shade structures for us the last couple of years.

Links

Geodesic Domes

• Tara Landry’s Desert Domes site. Dome calculator. EMT dome frame kits for sale.
• Kerry’s wooden-frame 2V dome. Photos
• Kerry’s dome building article. (AEZ mail list archive, password required. Date:Mon May 29 19:37:51 PDT 2006)
• Cardboard Dome, very complete how-to.

Non-geodesic Domes

• Shelter Systems. Complete dome kits for sale.
• http://www.geocities.com/polydomes/build-t10.htm Directions for a bent PVC pipe dome. Scale it up or down for your needs!

Gypsy Bender Tent

• http://www.enslin.com/rae/gypsy/bender.htm

Very awesome easy-to-build style of tent that can be made with PVC pipe and a couple of pieces of lumber. Alexxis in the AEZ has a great bender tent that she brings every year.

Tipis

• http://www.tipi.com/

Nomadic Tipi Makers in Central Oregon. These are one of the sturdiest structures on the playa!

General Shade Discussion

• http://tribes.tribe.net/shadegeeks